1.5 HP vs 3HP Pump

[Nochain]

Trying to determine what HP I need and if a 1.5HP will be more efficient than a 3HP.

My Pool specs
18K Gal
2 floor drains
1 side vac port
1 skimmer
1 water feature running off a 2in pipe (rock fall)
1 smaller sprinkler running off a 1-inch line
Currently have a single speed 1.5HP pump (works well)

I passed fluid dynamics but just barely lol

 

[mas985]

If you are talking about a VS pump, the larger pump is going to be more efficient and quieter at a given flow rate.

If you are talking about another single speed pump, it is unlikely you will find one given current DOE regulations. They are not allowed to be manufactured in the US over a certain HP rating:

Pump DOE Regulations - Further Reading

www.troublefreepool.com

 

[Nochain]

If you are talking about a VS pump, the larger pump is going to be more efficient and quieter at a given flow rate.

If you are talking about another single speed pump, it is unlikely you will find one given current DOE regulations. They are not allowed to be manufactured in the US over a certain HP rating:

Pump DOE Regulations - Further Reading

www.troublefreepool.com

Yes speaking strictly about VS pumps.

 

[Nochain]

So if my single speed 1.5HP was good enough for everything in my system then it as simple as using a 1.5HP VSP to replace it? If I dont need a 3HP I would assume its more efficient to run a 1.5HP rather than stepping needlessly up to a 3HP (again assuming the 1.5HP was good enough)?

 

[ajw22]

A 3 HP pump running at 1.5 Hp is more efficient than a 1.5 HP pump running at 1.5 HP.

 

[mas985]

More efficient AND quieter. The larger VS is always a better choice.

 

[trivetman]

I replaced my 1.85 hp single speed with 2.5 hp vsp this summer. It is plenty quiet at low speeds. While maybe there are some efficiency arguments to be made for getting the biggest vsp out there, my 2.5 is plenty efficient and quiet at low speeds and i am very happy not spending the extra cash. In hindsight I might have been ok dropping down to the 1.5 model but theres no do-overs once you hit purchase and the 2.5 model wasnt much more expensive